JPS6140073A - Solid laser oscillator - Google Patents

Abstract

PURPOSE:To improve the laser oscillation efficiency and reduce the overall length of a solid laser element, by forming a plurality of slanting surfaces on each end face of a rectangular plate-shaped solid laser element, each slanting surface slanting in a direction which is different from the direction of travel of the laser beam output from the laser element. CONSTITUTION:A solid laser element 11 has a rectangular plate-shaped configuration. Excitation surfaces 12 which are irradiated with the excitation light radiated from excite lamps are respectively formed on both side surfaces of the element 11. The excitation surfaces 12 are optically polished. Two pairs of slanting surfaces 13a, 13b and 14a, 14b are formed by optical polishing, each of these surfaces slanting in a direction which is different from the direction of travel of the laser beam output from the element 11. The pairs of slanting surfaces 13a, 13b and 14a, 14b respectively define angular laser beam incident/emergent end parts 15, 16 each projecting outwards at a substantially central portion thereof. A highly reflective part 17 which totally reflects the laser beam is disposed in opposing relation to either of the end parts 15 or 16, and a laser beam emerging part 18 which can transmit a part of the laser beam and reflect the remaining beam is disposed in opposing relation to the other. Thus, it is possible to improve the laser oscillation capability and reduce the overall length of the laser element 11.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to an improvement of a solid-state laser oscillation device equipped with a rectangular plate-shaped solid-state laser element.

[Technical background of the invention and its problems]

Generally, a solid-state laser oscillation device includes a solid-state laser element 1 formed in the shape of a rectangular plate with a vertical dimension a, a horizontal dimension b (b≧2a), and a length dimension 1, as shown in FIGS. 5 and 6. , excitation surfaces 2 formed on both sides of this solid-state laser device 1
．． 2 is irradiated with excitation light emitted from an excitation lamp (not shown), and a high reflection part 3 which totally reflects the laser light toward one end side of the solid-state laser element 1. Laser light emitting section 4 that can transmit part of the laser light to the other end and reflect/reflect the rest
are arranged facing each other, and furthermore, the solid-state laser element 1 and
Slanted surfaces 5.5 on both end faces are inclined at a predetermined inclination angle θB with respect to the traveling direction of the laser beam output from the solid-state laser element 1.
is formed, and when the excitation light emitted from the excitation lamp is irradiated onto the excitation surfaces 2, 2 of the solid-state laser device 1, the laser beam excited inside the solid-state laser device 1 is directed to the inclined surfaces 5, 2.
5, each excitation surface 2 of the solid-state laser element 1 is refracted when passing through the
．． A structure is known in which the laser beam advances and oscillates while repeating total reflection on the laser beam. In this case, the inclination angle θB of the inclined surfaces 5 at both ends of the solid-state laser device 1 is set to an angle at which total reflection of the incident laser beam can occur on each excitation surface 2.2 of the solid-state laser device 1.

By the way, when the inclination angle θB of the inclined surface 5.5 of the solid-state laser device 1 is set large, the number of reflections of the laser beam inside the solid-state laser device 1 decreases, and the length of the laser optical path inside the solid-state laser device 1 decreases. Since the length becomes relatively short, there is a problem that the length dimension I of the solid-state laser device 1 becomes long. Therefore, when the length dimension of the solid-state laser element 1 is made relatively small, the inclination angle θB of the inclined surface 5.5 is set relatively small to increase the number of reflections of the laser beam inside the solid-state laser element 1. It is necessary to increase the length of the laser optical path inside the laser element 1. However, in the conventional structure described above, the solid-state laser element 1
Since the sloped surfaces 5.5 at both ends of the solid-state laser element 1 were formed only in one direction, the number of reflections of the laser beam inside the solid-state laser element 1 was increased by setting the slope angle θB of the sloped surfaces 5.5 to be relatively large. In some cases, the portion of the solid-state laser device 1 that does not directly contribute to laser oscillation, that is, the portion that does not form a laser optical path, is 30 to 40 of the entire solid-state laser device 1.
%, and there was a problem that the laser oscillation efficiency deteriorated.

[Purpose of the invention]

The present invention can reduce the proportion of the portion inside the solid-state laser device that does not directly contribute to laser oscillation, improve the laser oscillation efficiency, and shorten the overall length of the solid-state laser device. The object of the present invention is to provide a solid-state laser oscillation device that can perform the following steps.

[Summary of the invention]

This invention is characterized in that a plurality of inclined surfaces are formed on both end faces of a rectangular plate-shaped solid-state laser element, each inclined in a different direction with respect to the traveling direction of laser light outputted from the solid-state laser element. .

[Embodiments of the invention]

FIGS. 1 and 2 show an embodiment of this invention. In FIGS. 1 and 2, 11 is a solid-state laser element formed in the shape of a rectangular plate with a vertical dimension a, a horizontal dimension b (b≧2a), and a length dimension 1. Excitation surfaces 12.12 are formed on both sides of the solid-state laser element 11, and are irradiated with excitation light emitted from an excitation lamp (not shown). These excitation surfaces 12.12 are optically polished so that efficient total reflection can occur inside them. Furthermore, this solid-state laser element 1
A pair of inclined surfaces 13a, 13b, and 14a are provided at both ends of the solid-state laser element 11, respectively, and are inclined in a direction opposite to the traveling direction of the laser beam output from the solid-state laser element 11.

14b are formed by optical polishing, and each pair of inclined surfaces 13a, 13b, 14a.

14k), laser beam input/output ends 15 and 16 each having a substantially chevron shape (apex angle θW) whose substantially central portion protrudes outward are formed, respectively. Also, at the laser light input/output ends 81115.16 at both ends of the solid-state laser element 11, high reflection portions 17. On the other end side, laser light emitting sections 18 that can transmit a part of the laser light and reflect the rest are arranged facing each other.

This high reflection section 17 is formed by a right angle prism reflector. Further, the laser beam emitting section 18 includes one inclined surface 14 of the laser beam input/output end 16 of the solid-state laser element 11.
Output 1111 with partial transparency in the upper half facing a
9. A total reflection mirror 2 is provided in the lower half facing the other inclined surface 14b.
0 is common.

Therefore, in the structure described above, the excitation light emitted from the excitation lamp is irradiated onto the excitation surface 12.12 of the solid-state laser element 11 as shown by the arrow in FIG. The laser light excited inside the solid-state laser element 11 is refracted when passing through each pair of inclined surfaces 13a, 13b, 14a, and 14b of the laser light input/output ends 15 and 16 of the solid-state laser element 11, and is refracted into the solid state. The laser beam advances and oscillates while repeating total reflection on each of the five excitation surfaces 12 and 12 of the laser element 11. In this case, since the high reflection section 17 is formed by a right angle prism reflector, one inclined surface 13a of the laser beam input/output end section 15 (
Alternatively, the laser beam component emitted from the side 13b) is reflected by both reflective surfaces 17a, 17b (17b, 1
7a) and are incident on the other inclined surface 13b (13a) of the laser light input/output end portion 15. Furthermore, the laser beam emitting section 18 includes an output mirror 19 on the upper half side that is partially transparent, and a solid-state laser element 1.
Since it is formed by one inclined surface 14a of the laser beam input/output end 16 of No. 1 and the total reflection mirror 20 on the lower half side,
The laser beam component emitted from one inclined surface 14b side of the laser beam input/output end 16 is totally reflected 1 by the laser beam output section 18.
120 and enters again from the same inclined surface 14b side, and a part of the laser beam component emitted from the other inclined surface 14a side of the laser beam input/output end 16 is output l! 19 and enters again from the same inclined surface 14a side, and the rest is taken out to the outside via this output mirror 19.

Thus, in the structure described above, the solid-state laser device 1
Since the laser optical path can be formed throughout the interior of the solid-state laser element 11, the entire interior of the solid-state laser element 11 can contribute to laser oscillation, and the laser oscillation efficiency can be improved compared to the conventional method.

Furthermore, since the entire interior of the solid-state laser device 11 can be used as a laser optical path, the solid-state laser device 11
Approximately twice as many laser optical paths can be formed inside the solid-state laser element 11 as compared to the conventional one, and the overall length of the solid-state laser element 11 can be shortened.

Note that this invention is not limited to the above embodiments. For example, in the above embodiment, the laser beam component totally reflected by the total reflection 120 of the laser beam emitting section 18 is emitted from the upper inclined surface 13a of the laser beam input/output end section 15, and then is emitted from both stages of the right angle prism reflector. Although a structure is shown in which the laser beam is reflected by the surfaces 17a and 17b and is made incident on the lower inclined surface 13b of the laser beam input/output end portion 15, as shown in FIG. After the laser beam component totally reflected by the mirror 20 is emitted from the lower inclined surface 13b of the laser beam input/output end 15, the laser beam component is emitted from the lower slope surface 13b of the right angle prism reflector.

It may be configured such that the laser beams are reflected by the respective laser beams 17a and made to enter the upper inclined surface 13a of the laser beam input/output end portion 15. Further, as shown in FIG. 4, the high reflection section 21 may be formed of a dielectric mirror for total reflection, and the entire surface of the laser beam emitting section 22 may be formed of an output mirror that is partially transparent. In this case, the entire interior of the solid-state laser element 11 can be used more effectively for laser oscillation.

Furthermore, three or more inclined surfaces at both ends of the solid-state laser element 11 may be formed, and it goes without saying that various other modifications can be made without departing from the gist of the present invention.

〔Effect of the invention〕

According to this invention, a plurality of inclined surfaces are formed on both end faces of a rectangular plate-shaped solid-state laser device, each inclined in a different direction with respect to the traveling direction of laser light emitted from the solid-state laser device. The proportion of the internal portion that does not directly contribute to laser oscillation can be reduced, the laser oscillation efficiency can be improved, and the overall length of the solid-state laser element can be shortened.

[Brief explanation of drawings]

1 and 2 show one embodiment of the present invention, FIG. 1 is a side view showing a schematic configuration of the main part, and FIG.
3 is a side view showing another embodiment, FIG. 4 is a side view showing still another embodiment, and FIGS. 5 and 6 are a conventional example. , FIG. 5 is a side view showing a schematic configuration of the main parts, and FIG. 6 is a cross-sectional view taken along the line Vl--Vl in FIG. 5. 11... Solid-state laser element, 12... Excitation surface, 13a
. 13b, 14a, 14b・'slanted surface, 17.21...
- High reflection part, 18.22...Laser light emitting part.

Claims (1)

[Claims] A rectangular plate-shaped solid-state laser element has a high reflection part that totally reflects the laser beam at one end thereof, and a laser light emitting part that can transmit a part of the laser beam and reflect the rest at the other end thereof, and is arranged to face each other. Slanted surfaces that are inclined with respect to the traveling direction of the laser beam output from the solid-state laser device are formed on both end surfaces of the solid-state laser device, and when the laser beam excited inside the solid-state laser device passes through the sloped surface, In the solid-state laser oscillation device, the solid-state laser oscillation device advances and oscillates while repeating total reflection on each side wall surface of the solid-state laser element. A solid-state laser oscillation device characterized in that a plurality of inclined surfaces are formed, each of which is inclined in a different direction.